1. Field of the Invention
The invention relates to methods and apparatus for control of cell growth, including angiogenesis, in porous implants, produced from ceramics, of the low density type from the general family described in Banas, et al, Thermophysical and Mechanical Properties of the HTP Family of Rigid Ceramic Insulation Materials, AIAA 20th Thermophysics Conference, Jun. 19-21, 1985, Williamsburg, Va. (incorporated herein by reference), Creedon, et al., Strength and Composites, SAMPE Quarterly, October and (incorporated herein by reference), U.S. Pat. No. 4,148,962, issued to Leiser, et al. on April 1979 (incorporated herein by reference). As an example of the general family, a thermal insulation material is produced by Lockheed Missiles & Space Company, Inc. of Sunnyvale, Calif., having the following properties, according to what is believed to be an Occupational Health and Safety Administration Material Data Sheet of Feb. 28, 1989, as follows: